This invention relates to fire retardance and, in particular, although not exclusively, to fire retardant materials for application or incorporation in articles, for example for application to textiles and to textiles with such materials applied thereto.
Fire retardant materials for the application to textiles are well known. However, many of these materials are halogen-based (or at least contain halogens) and many can produce dioxin or dioxin-like compounds when exposed, in use, to heat.
Clearly, due to growing environmental concerns about the release of halogenated organic compounds into the environment, and more specifically to the potential for bio-accumulation of such materials and/or their degradation products, it is desirable to reduce the use of halogens in both material processing and in products.
Ammonium polyphosphate (APP) and APP-based systems are known halogen-free flame retardants mainly used in polyolefins (PE, PP), thermoset resins such as epoxy resins, polyurethane, unsaturated polyester phenolic resins and others. APP is a non-toxic, environmentally friendly material and it does not generate additional quantities of smoke due to the mechanism of “intumescence”.
Melamine-based flame retardants are becoming more popular as flame retardant materials. In this family of non-halogenated flame retardants, three chemical groups can be distinguished; pure melamine, melamine derivatives, i.e. salts with organic or inorganic acids such as boric acid, cyanuric acid, phosphoric acid or pyro/poly-phosphoric acid, and melamine homologues.
Melamine-based flame retardants show excellent flame retardant properties and versatility in use because of their ability to employ various modes of flame retardant action.
US 2002/0013391 A1 discloses a flame retardant resin coating comprising a flame retardant additive added to a base resin to provide a flame retardant base resin which is covered by a transparent top coat. The resins are for application to rigid substrates such as exterior cladding of buildings, wall facings, gravel stops, balcony facings, parapet slabs, wet rooms and laboratories. The additive may comprise melamine polyphosphates, melamine pyrophosphates, ammonium polyphosphates and mixtures thereof. In one embodiment, a suitable additive comprises an ammonium polyphosphate microencapsulated in a resin having a water solubility of from about 0.06 to about 0.19 g/100 g water.
EP 0131097 and U.S. Pat. No. 4,639,331 disclose the formation of microencapsulated ammonium polyphosphate to render the ammonium polyphosphate stable to hydrolysis. Microencapsulation is said to beneficially influence the use of such pre-treated ammonium polyphosphates as flame retardant agents in polyurethane foams.
EP 0966349 A1 discloses a flame retardant/heat resistant agent and adhesive, which includes one or more oxides of phosphorus, antimony, silicon and melamine cyanurate as the flame retardant agents and which can increase both the flame retardance/heat resistance of the cloth material and the binding strength of the cloth to a variety of thermoplastic polymers.
EP 0659819 B1 discloses a flame-retardant thermosetting resin composition containing a non-halogen type flame-retardant. In particular, it relates to a flame-retardant thermosetting resin composition having high water resistance and excellent mechanical properties which contains, as a non-halogen type flame-retardant, (1) melamine-coated ammonium polyphosphate particles and/or (2) water-insoluble ammonium polyphosphate particles.
It is an object of this invention to provide a fire-retardant material which is suitable for use in a plurality of embodiments, for example for application to textiles, and to an article, for example a coated or laminated textile material, in which the fire retardency is enhanced by the use in formation or application of such fire-retardant materials. It is a further, but not exclusive, object of the invention to provide a fire-retardant material which exhibits at least comparable although preferably improved performance over the prior art and one which, preferably, is at least as, if not more, environmentally friendly than prior art fire retardant materials.